This invention relates to a fuel pre-heater and, more particularly, relates to a fuel pre-heater for internal combustion engines.
The pre-heating of fuel, particularly diesel fuel, is well known. Diesel fuel typically contains paraffin wax which at low temperatures may solidify and precipitate out of the liquid fuel to plug fuel filters. Plugging of fuel filters and other obstructions to the free flow of fuel due to wax buildup causes starvation of fuel to the engine with resulting lack of engine power or stalling of the engine.
Warming of diesel fuel to about 120.degree. F. will effectively redissolve wax crystals from fuel filters and fuel lines to improve fuel flow while generally improving efficiency of combustion with reduction of smoke emission.
U.S. Pat. No. 4,231,342 discloses a diesel fuel control valve system in which a temperature responsive fuel control valve is used to control the flow of surplus heated fuel to either the fuel tank for the engine or to return the surplus fuel directly to the injectors for the engine.
U.S Pat. Nos. 4,359,972 and 4,386,584 relate to a thermostatically controlled valve in an axial flow conduit for controlling the rate of flow of coolant to regulate the temperature of propane gas fed to an internal combustion engine.
U.S. Pat. No. 4,372,260 discloses another embodiment of engine fuel heater mounted in a fuel line which makes use of heated water received from the engine cooling system to heat the fuel as it passes through the heater body. This Patent discloses the alternative use of a submersible electric heat element for heating fuel before it passes through a fuel filter.
It is an object of the present invention to provide a novel heat exchanger which contains a thermostatically controlled valve for controlling the temperature of fuel heated by the heat exchanger.
It is another object of the present invention to provide a thermostatically controlled heat exchanger which permits the facile exchange of thermostat valves for servicing or for easy change of temperature level.
These and other objects of the invention will become apparent from the following detailed description.